1. Field of the Invention
This invention relates to a method for the manufacture of antimony of the grade of the order of 99.99% by weight.
2. Description of the Prior Art
Antimony has found extensive utility as the hard lead in batteries, and in recent years, it has been increasingly used in electronic materials.
For example, it is used in Sn-Sb alloy solder for sealing ceramic packages on LSI's, in Hall devices, and in In Sb for infrared ray detectors. These electronic materials are required to possess high enough reliability that they will meet the trend of LSI's toward increased integration and decreased size. Consequently, antimony used in electronic materials must have a high purity.
Various methods for producing antimony of high purity are known. These include the electrolysis method, the metal distillation method, the oxide reduction method, and the zone refining method. Among these methods, the electrolysis method has found widespread recognition. By this particular method, antimony is produced in large quantities and marketed.
However, the electrolysis method, is not especially effective in separating out such impurities as arsenic and bismuth and it necessitates additional use of the zone refining method. In addition, the procedure involved is complicated and the cost of operation is high.